Watt Field Drainage SolutionsLibby Zanin, Benjamin Rawls, Emma Coleman

Objective ● Problem: Drainage issues on the field in front of

the Watt Innovation Center

● Design Goals:

○ Decrease ponding in the field

○ Control erosion and runoff 1

○ Maintain or increase aesthetics

Design Considerations

Soil Replacement● Cecil-Hiwassee-Pacolet,

general soils map of South Carolina from 19972

● Hydrologic Soil Group (HSG) B

● Moderate infiltration rate● Improve to HSG A

Drain Installation● University Solution

○ 3 drains● Remove 9 gallons per minute at

maximum3 ● From model 529 gallons per a

minute for just a 5 year storm ● Fast flow rate

○ erosion at site and discharge location

Land Management● Currently grass cover

● 7 revisions explored

with shrubs

○ Top and bottom

■ 20ft

■ 30ft

○ Complete cover

○ Top

■ 20ft

■ 30ft

○ Bottom

■ 20 ft

■ 30ft

Design Selection● Soil Replacement

○ Too expensive

○ Highly labor intensive

○ Hinders use of brand new building

● Drain Installation

○ Lack of erosion control

● *Land Management*

○ Low maintenance, non invasive option

○ Possibly increase aesthetics and functionality

○ Potential to decrease erosion

Methods

Methods● Determination of field size, slope, and soil type

○ Web Soil Survey

● Find Peak Flow Rate of 25 year storm

○ WNTR 55 Model

● Determine the amount of runoff and sediment loss from

each land management revision

○ WEPP Models

WNTR 55 Model

WEPP Models

Results

WEPP Model Results SummaryLand Management Average Annual Runoff (in) Average Annual Soil Loss (ton/A)

Current- Grass 7.18 0.474

Shrubs at Top (20ft) 6.97 0.448

Shrubs at Top (30ft) 6.85 0.444

Shrubs at Bottom (20ft) 6.88 0.523

Shrubs at Bottom (30ft) 6.89 0.590

Shrubs at Top & Bottom (20ft) 6.36 0.470

Shrubs at Top & Bottom (30ft) 6.11 0.527

Shrubs Complete Cover 5.51 0.346

Chosen Land Management● Shrubs complete cover

chosen

○ Erosion reduced by 27% ○ Runoff reduced by 23%

● Theoretical design would include sitting areas along with plants

Relevance to Hydrology & Importance of Project

Relevance & Importance ● Universal Annual Soil Loss Equation: T = R K LS VM

○ Soil replacement- K- soil erodibility factor

○ Land management- VM- vegetative mulch factor

● Land management to reduce

erosion

● Watt is LEED-silver certified

○ Usable open space can add

points to the scorecard

Conclusions

Conclusions● Solution: Revised landscaping of Watt Field

○ Plant:

■ Shrubs

■ Perennials

■ Trees

○ Create usable open space:

■ Benches

■ Tables

● Design Goals:

○ Improves aesthetics and functionality of space

○ Decreases runoff and erosion (23%, 27%)

Questions?

References1Brander, K. E., Owen, K. E., & Potter, K. W. (2004). Modeled Impacts Of Development Type

On Runoff Volume And Infiltration Performance. Journal of the American WaterResources Association J Am Water Resources Assoc, 40(4), 961-969.doi:10.1111/j.1752-1688.2004.tb01059.x

2General soil map of South Carolina, 1997 [Map]. (1997). Columbia, SC: South Carolina Dept.of Natural Resources, Land Resources and Conservation Districts Division. RetrievedApril 10, 2016, from http://www.ces.clemson.edu/scmaps/cartography/DigitizedMaps/SoilsMap.jpg

3University of Minnesota. (2016). Drainage calculator. Retrieved April 23, 2016, fromhttp://www.extension.umn.edu/agriculture/water/online-calculator/#flowrate